Uncaught ReferenceError: process is not defined after resize

I recently ran into a memory issue so I had to resize my droplet. Since then I just get a blank page at my url and the Chrome dev console tells me process is undefined.

I ran npm run build on my create-react-app react app and it is now live on my digital ocean droplet, but I keep getting an error in the console

index.js:6 Uncaught ReferenceError: process is not defined
at Object.<anonymous> (index.js:6)

The line of code it refers to is:

const {env} = process;

which looks like it was automatically generated in the build.

I’ve been building the app fine for months and nothing like this has ever happened!

My package.json is as follows:

{
  "name": "myapp",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@babel/core": "7.7.4",
    "@date-io/date-fns": "^2.6.1",
    "@date-io/moment": "^1.3.13",
    "@firebase/storage": "^0.3.32",
    "@fortawesome/fontawesome-svg-core": "^1.2.28",
    "@fortawesome/free-solid-svg-icons": "^5.13.0",
    "@fortawesome/react-fontawesome": "^0.1.9",
    "@google-cloud/storage": "^5.1.1",
    "@material-ui/core": "^4.9.11",
    "@material-ui/icons": "^4.9.1",
    "@material-ui/pickers": "^3.2.10",
    "@svgr/webpack": "4.3.3",
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.5.0",
    "@testing-library/user-event": "^7.1.2",
    "@typescript-eslint/eslint-plugin": "^2.29.0",
    "@typescript-eslint/parser": "^2.29.0",
    "algoliasearch": "^4.3.0",
    "ammonite-jspdf": "git+https://github.com/DavTho1983/jsPDF.git",
    "animate.css": "^3.7.2",
    "animate.css-react": "^1.0.0",
    "aws-sdk": "^2.663.0",
    "axios": "^0.19.2",
    "babel-jest": "^24.9.0",
    "babel-loader": "8.0.6",
    "babel-plugin-named-asset-import": "^0.3.6",
    "babel-preset-react-app": "^9.1.2",
    "blob-stream": "^0.1.3",
    "camelcase": "^5.3.1",
    "canvas2pdf": "^1.0.7",
    "case-sensitive-paths-webpack-plugin": "2.2.0",
    "chart.js": "^2.9.3",
    "chartjs-plugin-dragdata": "^1.1.3",
    "css-loader": "3.2.0",
    "date-fns": "^2.12.0",
    "dom-to-image-more": "^2.8.0",
    "dotenv": "8.2.0",
    "dotenv-expand": "5.1.0",
    "downloadjs": "^1.4.7",
    "emailjs-com": "^2.4.1",
    "eslint": "^6.8.0",
    "eslint-config-react-app": "^5.2.1",
    "eslint-loader": "3.0.2",
    "eslint-plugin-flowtype": "3.13.0",
    "eslint-plugin-import": "2.18.2",
    "eslint-plugin-jsx-a11y": "6.2.3",
    "eslint-plugin-react": "7.16.0",
    "eslint-plugin-react-hooks": "^1.6.1",
    "firebase": "^7.14.2",
    "firebase-admin": "^8.12.1",
    "firebase-functions": "^3.7.0",
    "fs-extra": "^8.1.0",
    "generate-password": "^1.5.1",
    "gsap": "file:gsap-bonus.tgz",
    "html-to-image": "^0.1.1",
    "html-webpack-plugin": "4.0.0-beta.5",
    "html2canvas": "^1.0.0-rc.5",
    "http2": "^3.3.7",
    "identity-obj-proxy": "3.0.0",
    "images-to-pdf": "^1.0.3",
    "jest": "24.9.0",
    "jest-environment-jsdom-fourteen": "0.1.0",
    "jest-resolve": "24.9.0",
    "jest-watch-typeahead": "0.4.2",
    "jspdf": "^1.5.3",
    "jszip": "^3.4.0",
    "layer": "^0.1.0",
    "material-ui": "^0.20.2",
    "mini-css-extract-plugin": "0.8.0",
    "moment": "^2.24.0",
    "node-fetch": "^2.6.0",
    "optimize-css-assets-webpack-plugin": "5.0.3",
    "pdfcrowd": "^4.12.0",
    "pnp-webpack-plugin": "1.5.0",
    "postcss-flexbugs-fixes": "4.1.0",
    "postcss-loader": "3.0.0",
    "postcss-normalize": "8.0.1",
    "postcss-preset-env": "6.7.0",
    "postcss-safe-parser": "4.0.1",
    "react": "^16.13.1",
    "react-app-polyfill": "^1.0.6",
    "react-chartjs-2": "^2.9.0",
    "react-dev-utils": "10.0.0",
    "react-device-detect": "^1.12.1",
    "react-dom": "^16.13.1",
    "react-recipes": "^1.0.0",
    "react-router": "^5.1.2",
    "react-router-dom": "^5.1.2",
    "react-scripts": "^3.4.0",
    "react-spinners": "^0.8.3",
    "react-swipeable": "^5.5.1",
    "react-uuid": "^1.0.2",
    "resolve": "1.12.2",
    "resolve-url-loader": "3.1.1",
    "sass-loader": "8.0.0",
    "semver": "6.3.0",
    "shortid": "^2.2.15",
    "style-loader": "1.0.0",
    "terser-webpack-plugin": "2.2.1",
    "ts-pnp": "1.1.5",
    "url-loader": "2.3.0",
    "webpack": "4.41.2",
    "webpack-dev-server": "^3.11.0",
    "webpack-manifest-plugin": "2.2.0",
    "workbox-webpack-plugin": "4.3.1"
  },
  "scripts": {
    "start": "node scripts/start.js",
    "build": "node scripts/build.js",
    "test": "node scripts/test.js"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  },
  "jest": {
    "roots": [
      "<rootDir>/src"
    ],
    "collectCoverageFrom": [
      "src/**/*.{js,jsx,ts,tsx}",
      "!src/**/*.d.ts"
    ],
    "setupFiles": [
      "react-app-polyfill/jsdom"
    ],
    "setupFilesAfterEnv": [
      "<rootDir>/src/setupTests.js"
    ],
    "testMatch": [
      "<rootDir>/src/**/__tests__/**/*.{js,jsx,ts,tsx}",
      "<rootDir>/src/**/*.{spec,test}.{js,jsx,ts,tsx}"
    ],
    "testEnvironment": "jest-environment-jsdom-fourteen",
    "transform": {
      "^.+\\.(js|jsx|ts|tsx)$": "<rootDir>/node_modules/babel-jest",
      "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
      "^(?!.*\\.(js|jsx|ts|tsx|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
    },
    "transformIgnorePatterns": [
      "[/\\\\]node_modules[/\\\\].+\\.(js|jsx|ts|tsx)$",
      "^.+\\.module\\.(css|sass|scss)$"
    ],
    "modulePaths": [],
    "moduleNameMapper": {
      "^react-native$": "react-native-web",
      "^.+\\.module\\.(css|sass|scss)$": "identity-obj-proxy"
    },
    "moduleFileExtensions": [
      "web.js",
      "js",
      "web.ts",
      "ts",
      "web.tsx",
      "tsx",
      "json",
      "web.jsx",
      "jsx",
      "node"
    ],
    "watchPlugins": [
      "jest-watch-typeahead/filename",
      "jest-watch-typeahead/testname"
    ]
  },
  "babel": {
    "presets": [
      "react-app"
    ]
  },
  "devDependencies": {
    "@fortawesome/fontawesome-free": "^5.13.0",
    "babel-eslint": "^10.0.3"
  }
}

My OS is Ubuntu 18.04.3 LTS. I have tried setting the node env with export NODE_ENV=production and when I run node and type process.env.NODE_ENV it says ‘production’.

I am using pm2 with the command pm2 serve build to serve the app, and nginx.